1. FIELD OF THE INVENTION
This invention relates to a railway bridge joint. More specifically, this invention relates to a three piece bridge joint having cast members which can be easily removed and replaced.
2. DESCRIPTION OF THE RELATED ART
Bridge joints are commonly used along a railroad track to allow a bridge structure to rotate horizontally. Such rotating bridges are an alternative to draw bridges. Bridge joints of the prior art have included a fixed point section, moveable point section, and a rocker arm that together maintain a substantially continuous surface on which the rail car rides. The rocker arm is pivotally attached to the moveable point section and rotates up away from the fixed point section to allow the bridge to rotate horizontally. The point sections are joined to the support substrate with planar base plates which are usually bolted to the support substrate and many times are integral to the sections. As the sections wear from rail car traffic they must periodically be removed and replaced. To remove such integral sections, the base plates must also be removed, which is a time consuming, costly process.
Other prior art bridge joints have sections that are bolted to the base plates. However, because these designs incorporate bolts that pass through the base plates, access to the underside of the base plates is required to remove the cast sections. If access is unavailable, the base plates must be removed with the rail sections before the sections can be removed from the base plates.
Thus, there is a need for a bridge joint having cast sections that can be easily and inexpensively replaced without requiring removal of the base plates.
The present invention is directed to a bridge joint having cast sections that can be its removed from the base plates and replaced without access to the underside of the base plates or bridge structure. The bridge joint has first and second planar base plates. A fixed point section is mounted to the first base plate and has an integral accepting portion with a point and flanges extending opposite the accepting portion. A moveable point section mounted to the second base plate has a yoke portion which has a point, pivot pin, and opening, and flanges extending opposite the yoke section. A rocker is pivotally attached to the moveable point section by the pivot pin in the yoke portion. The rocker has a fixed interface portion adapted to be received in the accepting portion of the fixed point section and a moveable interface portion adapted to be pivotally received in the yoke portion of the moveable point section. The rocker has slots adapted to accept the points at both interfaces, and the moveable interface has knuckles for pivoting on the pivot pin and a clevis connected to a lever activated by the bridge pivot mechanism.
A plurality of quick release fasteners are secured to the base plates for engaging the flanges and securing the fixed point section to the first base plate and the moveable point section to the second base plate. The fasteners are operated from an upper side. The fasteners have spring clips for engaging the flanges. The quick release fasteners have a base, and the flanges have notches adapted to engage the base.
A plurality of clamping lugs are positioned on the fixed point section and the moveable point section. A plurality of clamps correspond to the clamping lugs. The clamps have clamping plates adapted to engage and restrain vertical and horizontal movement of the clamping lugs and are releasably secured to the base plates. The clamps are operated from an upper side. There are clamping lugs on the accepting portion of the fixed point section and on the yoke portion of the moveable point section.
Both the moveable point section and the fixed point section have standard rail mating portions adapted to laterally abut and join with standard rail sections. The standard rail sections have a flange opposed to the mating portion which is secured to the base plate with the quick release fasteners. The accepting portion and the yoke portion have spaced side walls positioned closely adjacent to the interface portions of the rocker.